Motor starting switch



July 1 1924. Y

L. M. PERSONS MOTOR STARTING swITcH Filed OCT, '7

f l Il tual /A ,ww @y im; 8.., HW WM /m IMM, w i 2 5 C W n Y Patented July l, 1924.

UNITED STATES` PATENT o-FFICE.

LAWRENCE M PERSONS, F QUIN'CY, II'LINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 H. B. SHERMAN MANUFACTURING C0., OF BATTLE CREEK, MICHIGAN. A COB- PORATION OF MICHIGAN.

MOTOR STANTING SWITCH.

Applicatie; meaioctober ziele. serial No. 328,955.

To all whom it may concern:

Be it known that I, LAWRENCE M. PER- soNs, a citizen of the United States, residing at Quincy, inthe county of Adams and State of Illinois, have invented a certain new and useful Improvement in' Motor Starting Switches, of which the following is a specification.

My invention relates to a starting switch for electric motors and has for its object to provide a starting switch for split phase motors which is automatically cut out of action bythe acceleration of the rotation of the rotor.- Other objects will appear from time to time inthe speciication.

My invention is illustrated more or less: diagrammatically in the accompanymg" drawings wherein: Y I

Figure l is an elevation of my motor and starter with parts cut away;

A Figure 2 is an elevation of the starter and adjacent parts.

Figure 3 is an end view of my motor starter.

Like parts are'indicated by like gures and letters throughout.

A is a motor casing Withva base A1, enclosing the usual field A2 of a split phase motor and having any suitable plug connection A, on the removable end section or blade A4r of the casing. 'Mounted on the inside of the same casing are the stationary contacts Al5 A", illustrated as opposed copper strips.

B is a rotor of the usual type mounted on a shaft B1 and provided with lubricating means B3 B3. Rotatable on the rotor shaft and movable therealong, is the sleeve C, which has at either end, up-turned rims C1k C1. From the end and rim farthest from lthe'contacts A5, project the'opposed arms C2 C2, inclined toward the contacts, and terminating in enlarged ends C3 C'. Loosely `mounted on the sleeve,is an insulated ring normally composed of a conductive rim or facing C4 backed by a non-conductive backing and inner periphery C5. The disposition of the two parts is such that the conductive rim or face, although bridging the two contacts A", is thoroughly insulated from the sleeve and other working parts. A spring C6 coiled about the sleeve, presses the ring forward along the sleeve and against the contacts. f Y

Mounted on the rotor is the yoke D with eccentric bearings or hinges D1. MountedV therein are the centrifugal weights .D D2 in the form of curved blades slotted as at D3 to engage the arms C2. Springs D* D* tend to draw the weights or blades inwardly about the rotor axis. The rotation of the rotor throws the curved blades or weights D2 D2 eccentrically outward and moves the sleeve C and the ring C* axially away from the lixed contacts, by the engagement of the curved arms C2 by the slots D3. The enlarged ends of the arms limit the centrifugal excursion of the weights during motor rotation. Although I have illlustrated a working mechanism, it is obvious that many changes of shape and disposition of parts could be made without departing from the spirit of my invention, and I wish therefore, that my drawings and description may be regarded as iny a sense,l diagrammatic.

The use and operation of my invention are as follows:

My starting device is adapted for use with motors where a separate starting current or connection is used and more particularly, is useful with split phase alternating current motors. In this class of motor, it is desirable to start the motor by a connection which is broken before the motor approaches full speed. When the rotor is at rest, the insulated ring'forms a starting connection by its contact with the two stationary contacts against which it normally rests. When the current is thrown on, it bridges the two contacts, and starts the motor. The ring is forced against the contacts by the' coiled spring compressed 'between it and the opposite raised end of the sleeve on which it is mounted. The sleeveitself is normally forced in the direction of the contacts by the compression of the centrifugal weights, on the inclined arms of the sleeve. When the starting switch is thrown, the rotor, of course, begins rotation and rotates with it the collar or yoke carrying the switch govvses high speed,'centrifi1gal force is enough to oppose the weight compressing springsA and to carry the weights out from their normal position about the rotor axis. Since they arev slotted to enga e the arms on the ring carrying sleeve an -since those arms are inclined toward the ring and terminals engaged thereby, the outward movement of'v the weights withdraws the sleeve and ring and almost instantaneously breaks the starting current. The starting mechanism operates with the rotor. When rotation ceases the weights are actuated by their springs, the sleeve is forced forward, and the ring bridges the contacts. -It reaches' the contacts before it has ceased rotation and makes a partial revolution while in contact with them. This form of switch is extremely reliable because the ring makes a partial revolution on the stationary contacts after each revolution. of the rotor and thus wipes them free from dust, grease, oxides or any other foreign matter which tends to accumulate thereon. Since the ring is rotatable on the sleeve on which it is mounted,.it comes to rest before the rotor, and thus brings the wear of the contacting parts to a minimum,

and insures a practically permanent close contact of ring and contacts. The thorough insulation of the ring with its large cross section of insulating 'material prevents grounding. The switch being inside of the sure.

I claim':

.1. In a starting switch for motors, a rotor, a plurality of starting circuit contacts, means for connecting said contacts when the motor is at rest, comprising an axially movable -sleeve concentric with the rotor, a ring rotatably and axially movable thereon, and adapted to connect said contacts, yielding means mounted upon said sleeve adapted to hold said ring at the end 'of the sleeve adjacent said contacts, and centrifugal means rotated by the rotor for A rotor casing is protected from blows or preswithdrawing said sleeve and ring from said i contacts.

2. In a' starting switch for motors, a rotor,A a plurality of starting circuit contacts, means for connecting said contacts when the motor is vat rest, comprising an axially movable sleeve concentric with the rotor, a ring rotatably and axially movable thereon, and adapted to connect said contacts, yielding means mountedupon said sleeve adapted to, hold` said ring at the end of the sleeve adjacent said contacts, and centrifugal means rotated by the rotor for withdrawing said sleeve and ring from said contacts, comprisirg a pair .of opposed hinged centrifugal arms, and yielding means normally drawing their ends toward the roter exis 3. In a starting switch for motors, a Vrotor, a plurality of starting circuit contacts, means for bridging said contacts comprising a ring, means for holding it normally against the contacts, and means adapted during rotation of Ithe rotor to Withdraw the ring from the contacts, comprising arms in connection with the ring inclined toward the contacts, and centrifugal means pivoted to the rotor adapted slidingly toengageisaid arms.

4. In a starting switch for motors, a rotor, a plurality of starting circuit contacts, means for bridging said. contacts comprising a sleeve', an insulated ring rotatable thereon, means for normally holding said ring against the contacts, means adapted during rotation of the rotor to withdraw the ring from the contacts, comprising arms on the sleeve inclined toward the contacts, and centrifugal means pivoted to the rotor adapted c slidingly to engage said arms.

y 5. In a starting switch for motors, a rotor, a plurality of lstarting circuit contacts, means for connecting said contacts comprising a sleeve, an -insulated ring rotatable thereon, yielding means normally forcin the ring against the contacts, means adapte durin rotation of the rotor, to withdraw the I ring l om the contacts, comprising arms on the sleeve inclined toward the contacts, centrifugal weights mounted on the rotor and tion of the rotor,'to draw the weights to-.

ward the aXis of rotation of the rotor.

7. In a starting switch for motors, a plurality of starting circuit contacts, a. rotor and shaft, means for connecting said contacts when the motor is at rest, comprising a sleeve rotatable on the rotor shaft and movabletherealong, an insulated ring movable on the sleeve, yielding means for holding the ring against the contacts when the rotor is at rest, and centrifugal means for withdrawing the sleeve and ring along the rotor shaft during rotation comprising a pair of opposed centrifugal weights adapted to rotate ip1 aft plane perpendicular to the axis of the' s a .8.' In a starting-switch for motors, a plu- I rality of. starting circuit contacts, a rotor and shaft, means for connecting said contacts when the motor is at rest, comprising a A sleeve on the rotor shaft and movable there- 4 along, an insulated ring axially movable and rotatable on the sleeve and yielding means mounted upon said sleeve and movable with it, ada ted normally to hold said ring at the en of the sleeve adjacent said starting contacts.

9. Ina starting switch for motors, a rotor, a: plurality of startin circuit contacts, means for connecting sai l sleeve, an insulated ring rotatable thereon, yielding means normally forcing the ring against the contacts, means adapted, during rotation of the rotor, tovwithdraw the ring from the contacts, comprising arms on the sleeve inclined toward the contacts, weights pivoted on the rotor and slotted to engage the arms, and means at the ends of the arms adapted for limiting the centrifugal excur sion of the weights.

10. In a startin switch for motors, a ro-l tor, a plurality o starting circuit contacts, means for connecting said contacts when the motor is at rest, com rising a ring concentric with the rotor an rotatable in relation thereto, vielding means for forcing said ring vagainst said contacts, and means adapted to withdraw said ring and said yielding means axially away from said contacts, in response to a pre-determined speed of rotation of the rotor, comprising centrifugal weights pivoted at points spaced from the axis of rotation of the rotor and adapted to rotate in. a plane perpendicular thereto.

11. In a starting switch for motors, a plurality f starting contacts, a rotor and means for connecting said contacts when the rotor is at rest, comprising a sleeve rotatable on the rotor shaft and movable therealong, an insulated ring, axially and rotatably movable on the sleeve, inclined members in connection with said sleeve, centrifugal elements in contact with said inclined members, andadapted to centrifugally move in a plane perpendicular to the axis of the rotor.

12. In a starting switch for motors, a plurality of starting contacts, a rotor and means for connecting said contacts when the rotor is at rest, comprising a sleeve rotatable on the rotor shaft and movable therealong, an

insulated ring axially and rotatably movable on the sleeve, inclined members in connection with said sleeve, slotted centrifugal elements in contact with said inclined members, and adapted to centrfugally move in a plane perpendicular to the axis of the rotor, said inclined elements adapted to pass through said slotted members.

13. In a starting switch for motors, a plurality of starting'` circuit contacts, a rotor and shaft and means for connecting said contacts when thel rotor is at rest comprising a sleevev rotatable on the rotor shaft and movable therealong and a contact 'bridging element in contact therealong, inclined arms contacts comprising a i outwardly projecting from said sleeve, slotted centrifugal elements adapted to engage said arms by said slots and nrlanted to be moved outwardly in a plane perpendicular to the axis of rotation of the rotor.

14. A motor starting switch comprising a motor shaft, centrifugally swinging weights connected to rotate with said shaft, a pair of fixed contacts, a ring slidably mounted on said shaft and having radially extending arms, and a contact operatively connected with said swinging weights by said ring and arms and arranged to be moved by said ring into and out of engagement with said `fixed contacts. l

l5. A motor starting switch comprising a motor shaft, a pair of weights mounted for swinging toward and away from said shaft, a contact mounted for sliding longitudinally with respect to the shaft, a iixed contact, and a connection ,between saidswinging weights and said first-mentioned contact for moving the latter into and out of engagement with the lixed contact, said connection comprisin a ring slidably mounted on said shaft an having radially extending arms loosely engaging said weights.

16. A starting switch comprising a motor shaft; a weight mounted for swinging toward and away from said shaft; a ring around said shaft and'slidable thereon; an arm on said ring engaging said weight; a fixed contact; and a contact carried by said ring and movable thereby into engagement with said fixed contact. f

17. In a motor, a'ixed contact, a rotating contact slidable to and from said ixed contact, a radially extending member connected to said rotating contact and inclined longitudinally of the axis of the latters rotation, a weightedy arm rotatable with said rotating contact, pivoted to swing transversely of theaxis of rotation at a predetermined rotating speed, vand positioned to engag said member, as it swings, to move thf. at ter and said rotating Contact along the axis of rotatiori. Y

18. In a centrifugal sarting switch radially movable weighs adapted to be attached to a rotatable part, a member movable axially of said part, and interengageable members carried by the weight and said axially movable member whereby when the weight is moved outwardly the member is moved inwardly and vice versa; a .rotatable contact carried on said axially movable member, and

relatively fixed contact members adapted to y the motor and operated by centrifugal rotation, for engaging and movingsaid cam by and in proportion to the radial movement track members and said ring away from of the Weight-s. said contacts. In testimony whereof, I aix my signature 20. In a centrifugal starting switch, a roin the presence of tWo witnesses this 29th l tata'ble member, vmovable weights on said day of September, 1919.

member adapted to be moved outwardly by centrifugal 'fol-ce, a contact carrier movable LAWRENCEM' PERSONS' axially of said member, and engaging arms Witnesses: on the Contact carrier and weights whereby J. R. WILLIAMS,

Y 10 the contact carrier is caused to move axially R. T. WILLIAMS. 

